The proposed research will investigate pregnancy outcome after treatment of cervical dysplasia. Cervical dysplasia is a precancerous condition that can be effectively treated to prevent cancer of the uterine cervix. Incidence of cervical dysplasia peaks in women ages 25-35. Those with low-grade lesions are often not treated. The most common conservative treatment procedures are large-loop excision of the transformation zone (LLETZ), carbon dioxide laser conization, and carbon dioxide laser vaporization. There is presently insufficient evidence concerning the potential effect of these procedures on subsequent pregnancy outcome. The proposed research will investigate whether: 1) treatment of cervical dysplasia is associated with increased risk of preterm delivery in subsequent pregnancies; 2) whether treatment of cervical dysplasia is associated with specific subcategories of preterm delivery; 3) whether treatment of cervical dysplasia is associated with infertility, low birthweight, prelabor rupture of membranes at term, duration of labor and cesarean section rate; and 4) whether severity of dysplasia, length of cone, number of cervical treatments and interval between treatment and birth among treated women are related to adverse pregnancy outcome. The proposed research study has a retrospective cohort design. The cohort will consist of all women less than 45 years of age seen at the Colposcopy Clinic of Greenlane Hospital in Auckland, New Zealand, from 1989 through June 1998 who subsequently carried a singleton pregnancy beyond 20 weeks gestation. The cohort will be identified by linkage of the colposcopy and obstetric databases by means of a unique patient identification number. Outcome of the first >/= 20 week pregnancy following diagnosis will be compared for 535 treated women and 535 women not requiring treatment, using multiple logistic and linear regression models to control for confounding.